• 대한의용생체공학회:의공학회지
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• 제16권3호
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• pp.271-278
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• 1995

An ECG data compression algorithM using max-min slope update is proposed and a real time 3 channel ECG transmission system is implemented using the proposed algorithm. In order to effectively compress ECG data, we compare a threshold value with the max-min slope difference (MMSD) which is updated at each sample values. If this MMSD value is smaller than the threshold value, then the data is compressed. Conversely, when the MMSD value is larger than threshold value, the data is transmitted after storing the value and the length between the data which is beyond previous threshold level. As a result, it can accurately compress both the region of QRS, P, and T wave that has fast-changing and the region of the base line that slope is changing slow. Therefore, it Is possible to enhance the compression rate and the percent roms difference. In addition, because of the simplicity, this algorithm is more suitable for real-time implementation.

• 정보보호학회논문지
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• 제6권4호
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• pp.53-66
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• 1996

World Wide Web is a total solution for multi-media data transmission on Internet. Because of its characteristics like ease of use, support for multi-media data and smart graphic user interface, WWW has extended to cover all kinds of applications. The Secure Information Center(SIC) is a data transmission system using conventional cryptography between client and server on WWW. It's main function is to support the encryption of sending data. For encryption of data IDEA(International Data Encryption Algorithm) is used and for authentication mechanism MD5 hash function is used. Since Secure Information Center is used by many users, conventional cryptosystem is efficient in managing their secure interactions. However, there are some restrictions on sharing of same key and data transmission between client and server, for example the risk of key exposure and the difficulty of key sharing mechanisms. To solve these problems, the Secure Information Center provides encryption mechanisms and key management policies.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.317.2-317
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• 2002

Transmission loss of KHST passenger vehicle was calculated using measured acoustic data: In order to verify the transmission loss results for KHST case, similar experiment was carried out in laboratory condition, which result was compared those by geometric acoustic method. The computational results shows good agreement with the transmission loss magnitude from experiments. This paper also mentions items to obtain more accurate transmission loss values, i. e. how to assure reverberant field condition, the selection of source speaker' location.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권4호
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• pp.1854-1868
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• 2018

A wireless body-sensor network (WBSN) refers to a network-configured environment in which sensors are placed on both the inside and outside of the human body. The sensors are much smaller and the energy is more constrained when compared to traditional wireless sensor network (WSN) environments. The critical nature of the energy-constraint issue in WBSN environments has led to numerous studies on the reduction of energy consumption of WBSN sensors. The transmission-power-control (TPC) technique adjusts the transmission-power level (TPL) of sensors in the WBSN and reduces the energy consumption that occurs during communications. To elaborate, when transmission sensors and reception sensors are placed in various parts of the human body, the transmission sensors regularly send sensor data to the reception sensors. As the reception sensors receive data from the transmission sensors, real-time measurements of the received signal-strength indication (RSSI), which is the value that indicates the channel status, are taken to determine the TPL that suits the current-channel status. This TPL information is then sent back to the transmission sensors. The transmission sensors adjust their current TPL based on the TPL that they receive from the reception sensors. The initial TPC algorithm made linear or binary adjustments using only the information of the current-channel status. However, because various data in the WBSN environment can be utilized to create a more efficient TPC algorithm, many different types of TPC algorithms that combine human movements or fuse TPC with other algorithms have emerged. This paper defines and discusses the design and development process of an efficient TPC algorithm for WBSNs. We will describe the WBSN characteristics, model, and closed-loop mechanism, followed by an examination of recent TPC studies.

• 한국소음진동공학회논문집
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• 제16권11호
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• pp.1093-1099
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• 2006

In general, a measuring instrument of sound noise use only one wired channel by one sensor. Therefor the measuring instrument use wired cables as the number of channels are provided by instrument. In a point of observed target it needs data from multiple sensors and In case of measured point is a large numbers the environment of constitution would be complicated because that is in need of channel and cable. So we need the method that can improve the existing transmission channel and cable environment even the measured point is increased. If we use the Code Division Multiple Access(CDMA) we transmit a large numbers of sensor data by using a common transmission channel. We present the method that transmits data of multiple sensor to wireless by using CDMA. This method can simplify the measurement environment dramatically when collecting data by using multiple sensor. We expect this study to contribute the part of multiple access technology and relation technologies on the measuring environment.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.133-137
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• 2006

In general, a measuring instrument of sound noise use only one wired channel by one sensor. Therefor the measuring instrument use wired cables as the number of channels are provided by instrument. In a point of observed target it needs data from multiple sensors and In case of measured point is a large numbers the environment of constitution would be complicated because that is in need of channel and cable. So we need the method that can improve the existing transmission channel and cable environment even the measured point is increased. If we use the Code Division Multiple Access(CDMA) we transmit a large numbers of sensor data by using a common transmission channel. We present the method that transmits data of multiple sensor to wireless by using CDMA. This method can simplify the measurement environment dramatically when collecting data by using multiple sensor. We expect this study to contribute the part of multiple access technology and relation technologies on the measuring environment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.488-490
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• 2004

The technical data for transmission line design and maintenance are calculated by a very complicated numerical formula so it is almost impossible to solve them by hand. Therefore the TOWER+ EXPERT SYSTEM was developed to systematically support technical data for transmission line design and maintenance. This system is able to calculate technical data which is applied to all conductors in our county, - that is 12 kinds of systems with 86 numbers of standard conductors, - and is programed to be user friendly by adopting dialogue windows, menu selection functions. Moreover, it minimizes input data by automatically providing standard transmission line design data, and it includes guidance of applicable work, program usage, data input process, help, explanation of terms and automatic error recovery functions that even a beginner can easily use.

• International Journal of Computer Science & Network Security
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• 제21권3호
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• pp.83-93
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• 2021

COVID-19 poses a major risk to global health, highlighting the importance of faster and proper diagnosis. To handle the rise in the number of patients and eliminate redundant tests, healthcare information exchange and medical data are transmitted between healthcare centres. Medical data sharing helps speed up patient treatment; consequently, exchanging healthcare data is the requirement of the present era. Since healthcare professionals share data through the internet, security remains a critical challenge, which needs to be addressed. During the COVID-19 pandemic, computed tomography (CT) and X-ray images play a vital part in the diagnosis process, constituting information that needs to be shared among hospitals. Encryption and image steganography techniques can be employed to achieve secure data transmission of COVID-19 images. This study presents a new encryption with the image steganography model for secure data transmission (EIS-SDT) for COVID-19 diagnosis. The EIS-SDT model uses a multilevel discrete wavelet transform for image decomposition and Manta Ray Foraging Optimization algorithm for optimal pixel selection. The EIS-SDT method uses a double logistic chaotic map (DLCM) is employed for secret image encryption. The application of the DLCM-based encryption procedure provides an additional level of security to the image steganography technique. An extensive simulation results analysis ensures the effective performance of the EIS-SDT model and the results are investigated under several evaluation parameters. The outcome indicates that the EIS-SDT model has outperformed the existing methods considerably.

• 한국위성정보통신학회논문지
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• 제12권2호
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• pp.94-98
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• 2017

본 논문에서는 하이브리드 망 환경에서 부가데이터 서비스를 제공하기 위해 Mobile MMT를 기반으로 하는 송수신 구조를 설계한다. Mobile MMT는 차세대 멀티미디어 전송 프로토콜인 MMT의 확장된 표준이다. MMT는 IP를 기반으로 방송 통신이 융합된 방송시스템에서 멀티미디어를 효율적으로 전송하며, 다양한 형태의 데이터 전송 및 양방향 서비스를 지원하기 위한 기술들을 정의한다. Mobile MMT는 기존 MMT 기술을 기반으로 모바일 망에 특화된 기능을 제공하기 위해 확장된 기능을 추가로 정의한다. 이를 이용하여 본 논문에서는 방송망을 통해 전달받은 콘텐츠와 관련된 부가데이터와 단말정보와 관련된 교통, 날씨, 여행자정보 등의 부가데이터를 수신받을 수 있는 부가데이터 서비스 시나리오와 부가데이터의 송수신 구조를 설계하고 제안한다.

• 한국정보통신학회논문지
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• 제8권3호
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• pp.637-644
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• 2004

본 논문은 패킷 기반 네트워크의 유동적인 환경 변화와 전송하는 비디오 데이터의 특성을 함께 고려하여 비디오 데이터를 스트리밍하는 적응적 전송 미들웨어를 구현하고 성능을 평가하였다. 적응적 전송 미들웨어는 SR-RTP 기반의 스트리밍 모듈과 TFRC 기반의 전송률 제어 모듈로 구성되며, SR-RTP 기반의 스트리밍 모듈은 패킷 손실에 의해 손실된 비디오 데이터 중에서 중요도가 높은 데이터만을 선별적으로 재전송하여 패킷 재전송에 따른 전송 지연의 부담을 줄임과 동시에 패킷 손실에 따른 에러를 크게 감소시킨다. TFRC 기반의 전송률 제어 모들은 TCP 기반의 데이터 전송과 정당하게 네트워크의 전송 대역폭을 공유하면서 최적의 전송 대역폭을 산출하여 전송률을 제어함으로써 유동적으로 변하는 전송 대역폭에 적응적으로 비디오 데이터의 전송률을 제어한다. 외부 인터넷 환경에서 적응적 전송 미들웨어를 적용하여 비디오 스트리밍을 실험하고 패킷 손실에 대한 복구 성능과 스트리밍 지터 정도를 측정하여 분석한 결과, 적응적 전송 미들웨어를 적용하지 않은 경우와 비교하여 상대적으로 높은 스트리밍 성능을 보였다.